Blackberry plant named ‘APF-77’

ABSTRACT

Description and specifications of a new and distinct blackberry cultivar named ‘APF-77’ which originated from seed produced by a hand pollinated cross of APF-12 (U.S. Plant Pat. No. 16,989)×Arapaho (U.S. Plant Pat. No. 8,510) is provided. This new blackberry cultivar can be distinguished by its primocane-fruiting trait with attractive, large fruit with excellent flavor, excellent plant health, and erect canes and enhanced performance for fruit set and development in high summer temperatures.

Latin name: Rubus subgenus Rubus Watson.

BACKGROUND

The new cultivar of blackberry called ‘APF-77’ is described herein. Thenew cultivar originated from a hand-pollinated cross of APF-12 (U.S.Plant Pat. No. 16,989)×Arapaho (U.S. Plant Pat. No. 8,510) made in 2001.The seeds resulting from this controlled hybridization were germinatedin a greenhouse in the spring of 2002 and planted in a field nearClarksville, Ark. (West-Central Arkansas). The seedlings fruited in thesummer of 2003 and one seedling, designated APF-77, was selected for itsprimocane-fruiting performance with attractive, large fruit withexcellent flavor, excellent plant health, and erect canes.

SUMMARY OF THE INVENTION

The new and distinct cultivar of blackberry originated from ahand-pollinated cross of APF-12 (U.S. Plant Pat. No. 16,989;female)×Arapaho (U.S. Plant Pat. No. 8,510; male) made in 2001 andlocated near Clarksville, Ark. (West-Central Arkansas). The botanicaldesignation of the new cultivar of blackberry is Rubus subgenus RubusWatson.

The seeds resulting from this controlled hybridization were germinatedin a greenhouse in the spring of 2002 and planted in a field nearClarksville, Ark. The seedlings fruited in the summer of 2003 onfloricanes and primocanes, and one seedling, designated APF-77, wasselected for its primocane-fruiting performance with attractive, largefruit with excellent flavor, excellent plant health, and erect canes.

During 2003, the original plant selection was propagated asexually fromroot cuttings at the above-noted location, and a test row of 40 plantswas established. Subsequently, larger test plantings have beenestablished with asexually multiplied plants at two locations inArkansas. Additionally, the cultivar has been tested at test plots inLincolnton, N.C., Watsonville, Calif., State College, Pa., Frankfort,Ky., and Aurora, Oreg., and at each location propagation was from rootcuttings from the Clarksville, Ark. test plot.

The new cultivar has been asexually multiplied annually since 2003 bythe use of root cuttings and by rooting adventitious shoots from rootcuttings. It forms new shoots from adventitious buds on root cuttingsreadily. During all asexual multiplication, the characteristics of theoriginal plant have been maintained and no aberrant phenotypes haveappeared.

Test plantings over a wide geographic area have shown this new cultivarto be adapted to differing soil and climatic conditions. Further, itsprimocane-fruiting performance is substantially better in more moderatesummer climates such as Aurora, Oreg. and Watsonville, Calif., asevidenced by larger fruit weight and higher yields compared toClarksville, Ark. However, fruit set of the new cultivar has usuallybeen better than other primocane-fruiting blackberries when temperaturesduring flowering and fruit development exceeded 29.4-32.2° C. (85-90°F.). A key differentiation of the new cultivar and its parent Arapahoand most other blackberry cultivars that are floricane-fruiting is thatthe primocane-fruiting plant produces fruit on current-season canes(primocanes), and the portion of the cane that does not fruit in thecurrent season will fruit the following season (floricane fruiting).

BRIEF DESCRIPTION OF THE PHOTOGRAPHS

The accompanying photographs show typical specimens of the new varietyin color as nearly true as it is reasonably possible to make in a colorillustration of this character. The plants in the drawings were 5 yearsold.

FIG. 1 is a photograph a blackberry cane of ‘APF-77’ in mid Augustshowing the primocane-fruiting character with unripe, green fruit, asexemplified by flower buds at the terminus of a primocane atWatsonville, Calif.

FIG. 2 is a photograph of ripe fruit on a primocane taken in earlyOctober near Clarksville, Ark.

FIG. 3. is a photograph of harvested primocane fruit taken in July, nearClarksville, Ark.

FIG. 4 is a photograph showing the adaxial side of a primocane leaf.

FIG. 5 is a photograph showing the abaxial side of a primocane leaf.

DETAILED DESCRIPTION OF THE NEW CULTIVAR APF-77

Plants and fruit of this new cultivar differ phenotypically from itsparents. The new cultivar has better flavor and overall fruit quality,larger berry size and is more productive with more intense andconsistent primocane-fruiting performance than the parent APF-12, andhas the primocane-fruiting trait expression not found in parent Arapaho.Parent Arapaho is thornless while the new cultivar has thorns. Althoughblackberries (Rubus subgenus Rubus Watson) are highly heterogeneous andoutcrossing, and most clones contain genes from more than one species,the new cultivar and its progenitor lines phenotypically exhibitcharacters predominately of the erect eastern United States species,Rubus allegheniensis Porter (highbush blackberry).

Plants of the new cultivar are vigorous and prolific and rowestablishment following planting is rapid. Both primocanes andfloricanes are erect in growth habit. The canes can be trained to aself-supporting hedgerow although it is beneficial to use a trellis withsupporting wires to prevent canes from falling over due to wind or heavyfruitloads. The plants are thorny. Plants and fruit are moderatelyresistant to anthracnose [Elsinoe veneta (Burkh.) Jenkins], and plantsappear immune to orange rust [Gymnoconia nitens (Schwein.) F. Kern andH. W. Thurston.]. No screening has been done for resistance to doubleblossom/rosette [Cercosporella rubi (Wint.) Plakidas]

The floricane and primocane bloom periods of the new cultivar begin onthe same date and averages the same length as APF-12. Primocane bloom ofthe new cultivar has been observed to be more intense in Arkansascompared to APF-12, particularly in summer temperatures over 90° F.

Floricane fruit of the new cultivar begins ripening at the same time asAPF-12 and can extend 10 days later than APF-12 due to the commonemergence of basal fruiting canes providing for the more extendedfruiting period. Average first ripening date is 2 June in West-CentralArkansas. The average floricane fruiting period is 40-50-days. Averagefirst primocane fruit ripening date is 15 July in West-Central Arkansas.In Aurora, Oreg., first primocane fruit ripening date averaged Sept. 10.

Fruit yields of the new cultivar on floricanes are usually 3 to 4 kg(6.0 to 9.0 lb/plant) if the floricanes are retained for fruiting,exceeding that for APF-12, in West-Central Arkansas. Fruit yields of thecultivar on primocanes in West-Central Arkansas range from 0.2 to 1.0 kg(0.4 to 2.2 lb/plant) and exceed that of APF-12. On primocanes inAurora, Oreg., yield averaged 3.0 kg (6.6 lb/plant), and in Watsonville,Calif. averaged 3.9 kg (8.6 lb/plant). The difference in primocaneyields are believed to be due to temperatures in Oregon and Californiatest locations being more moderate during primocane flowering andfruiting compared to West-Central Arkansas. The increased yield of thenew cultivar over that of APF-12 in Arkansas is believed to be due tohigher heat tolerance of flowers and fruit.

The fruit is slightly conical in shape, bright glossy black in color,and very attractive. The floricane fruit is medium-large (6-7 g/berry).Floricane fruit size of the new cultivar is maintained well throughoutthe entire harvest season. Primocane fruit in West-Central Arkansas ofthe new cultivar averaged 3.5 g/berry, while primocane fruit in Aurora,Oreg. averaged 9.1 g and in Watsonville, Calif. averaged 4.4 g.Primocane fruit size in West-Central Arkansas can be reduced in highsummer temperatures (exceeding 29.4-32.2° C./85 to 90° F.) but is moreuniform in the Oregon and California test sites. The new cultivarexhibits excellent fruit fertility with full drupelet set. The fruit ismoderately firm at maturity, comparable to that of APF-12. Storagepotential of fresh fruit of the new cultivar is not acceptable forshipping due to development of reddening of drupes, fruit softening andleakage during storage. The fresh fruit rates very good in flavor, andhigher than APF-12. The flavor is sweet and mildly acidic, with adistinct blackberry aroma. The soluble solids concentration averages10.2% on shiny black fruit, higher than APF-12 (9.1%) and hassubstantially reduced bitterness in the flavor profile compared toAPF-12.

Floricane fruit and flower clusters are medium-large, cymose, and aremostly borne on the periphery of the plant canopy, providing easy accessto harvest. Flower fertility is high and clusters are well filled.

Primocane fruit and flowers are borne on the cane terminus, and fruitingcontinues down the primocane during the season. Canes usually attain alength of approximately 122 cm (48 inches ft) prior to the appearance offlower buds. The number of nodes down the cane that develop flowers islargely dependent on the length and conditions of the late summer tofall growing period, particularly the field temperatures during thisperiod.

The following is a detailed description of the botanical and pomologicalcharacteristics of the subject blackberry. Color data are presented inRoyal Horticultural Society Colour Chart (1986 2^(nd) edition)designations. Where dimensions, sizes, colors, and other characteristicsare given, it is to be understood that such characteristics areapproximations of averages set forth as accurately as practicable.

Plants used for botanical data were 3 years old and grown on a finesandy loam soil with trickle irrigation at the Fruit Research Stationnear Clarksville, Ark. The plants were fertilized near budbreak (lateMarch on average) with complete or nitrogen fertilizer, and had anadditional nitrogen fertilizer application in early July. Primocaneswere tipped at approximately 107 cm (42 inches), and grown in a hedgerowtraining system. Weeds were controlled with pre- and postemergenceherbicides supplemented with mechanical weed control activities. Asingle application of liquid lime sulfur was applied to the plants atbudbreak, but no other fungicides were used. The descriptions reportedherein are from specimens grown near Clarksville, Ark. unless otherwisenoted.

-   Plant:    -   -   Size.—Plants are grown in a hedgerow and primocanes tipped            at approx. 107 cm (42 inches); plants in this system then            range in size from approx. 107-140 cm (42-55 inches) tall            and 91-102 cm (36-40 inches) wide.        -   Growth habit.—Moderate vigor, canes erect; suckers from            crown and roots.        -   Growth rate.—Primocanes reach tipping height (107 cm; 42            inches) on 1 June, approximately one month after emergence.        -   Productivity.—Floricane — 3 to 4 kg (6.0 to 9.0 lb/plant),            up to two times higher than APF-12. Primocane — 0.2 to 1.0            kg (0.4-2.2 lb/plant), higher than APF-12; At Aurora, Oreg.            3.0 kg (6.6 lb/plant) and Watsonville, Calif. 3.9 kg (8.6            lb/plant).        -   Cold hardiness.—Hardy to −13° C. (8° F.) or lower comparable            to slightly hardier than APF-12. The low temperature of            −13° C. (8° F.) was the lowest the cultivar has been exposed            to and fruited successfully after this exposure.        -   Canes.—Thorny, erect. Floricane (dormant or winter cane):            Cane diameter: base 0.85 cm; midpoint 0.67 cm; terminal            0.42 cm. Internode length: base 1.92 cm; midpoint 3.91 cm;            terminal 2.41 cm. Floricane color: base Yellow-Green Group            (146C); midpoint Yellow-Green Group (146C); terminus            Yellow-Green Group (146C). Thorn-density (per 30 cm of cane            length): base 19; midpoint 15.2; terminus 16.8. Thorn length            (from tip of thorn to bottom of thorn base): 6.2 mm; range            8.0-3.7 mm, with non-curved thorn. Primocane (current-season            cane): Cane diameter: base 1.16 cm; midpoint 0.93 cm;            terminal 0.20 cm. Internode length: base 4.22 cm; midpoint            3.93 cm; terminal 0.86 cm. Primocane color: base            Yellow-Green Group (146C) with some Red-Purple Group (60B);            midpoint Yellow-Green Group (146C) with some Red-Purple            Group (60B); terminus Yellow-Green Group (146C) with some            Red-Purple Group (60B). Thorn density (per 30 cm of cane            length): base 39.6; midpoint 23.8; terminus 5.5. Thorn            length (from tip of thorn to bottom of thorn base): 6.22 mm;            range 8.0-3.7, with non-curved thorn. Date of primocane            emergence: May 1.        -   Disease resistance.—Moderate resistant to anthracnose, and            plants appear immune to orange rust. No screening has been            done for resistance to double blossom/rosette.-   Foliage:    -   -   Primocane.—Leaves: large; mature compound leaf width 20.33            cm; length 19.86 cm. Leaflet: width 7.79 cm; length 13.11            cm; shape ovate with acute apex and subcordate base; margin            doubly serrated, serration teeth length 0.40 cm and width            0.41 cm; pubescence is light on abaxial and adaxial            surfaces; number of leaflets per compound leaf 3-5 with 5            most common. Color: base abaxial Yellow-Green Group (147B);            adaxial Green Group (137A); midpoint abaxial Yellow-Green            Group (147B); adaxial Green Group (137A); terminal abaxial            Yellow-Green Group (147B); adaxial Green Group (137A).            Petioles: length: 6.84 cm; color: Yellow-Green Group (146C);            texture smooth. Petiolules: length: 2.66 cm; color:            Yellow-Green Group (146D); texture smooth. Stipules: length:            1.43 cm; width: 0.18 cm; texture smooth.        -   Floricane.—Leaves: medium; mature compound leaf width 4.49            cm; length 4.38 cm. Leaflet: width 1.78 cm; length 3.09 cm;            shape ovate with acuminate apex and obtuse base; margin            doubly serrated, with serration teeth length 0.15 cm and            width at base 0.18 cm; pubescence is absent. Number of            leaflets per compound leaf is usually 3. Color: base abaxial            Yellow-Green Group (146C); adaxial Yellow-Green Group            (146B); midpoint abaxial Yellow-Green Group (146C); adaxial            Yellow-Green Group (146B); terminal abaxial Yellow-Green            Group (146C); adaxial Yellow-Green Group (146B). Petioles:            Length 1.25 cm; color: Yellow-Green Group (146D); texture            smooth. Petiolules: Length 0.31 cm; color: Yellow-Green            Group (146D); texture smooth. Stipules: Length 0.78 cm;            width: 0.15 cm; texture smooth.-   Flowers:    -   -   Floricane.—Date of bloom: 1^(st) bloom 1 April; full bloom            22 April; last bloom 1 May. Reproductive organs: Stamens —            erect, numerous. Pistils — numerous. Pollen — normal,            fertile, and abundant. Flower diameter: 4.41 cm. Petal size:            length 2.29 cm; width 1.63 cm. Petal color: White Group            (155B) and Greyed-Purple Group (186C). Average number            flowers per cluster: 8.3. Average number of petals per            flower: 8.5. Number of sepals per flower: 5.0. Peduncle            length: 1.97 cm. Peduncle color: Yellow-Green Group (146B).            Cyme type: simple cyme.        -   Primocanes.—Date of bloom: First bloom 10 June; Full bloom            June 20 but bloom can extend for very long and have            intermediate levels of intensity in the summer; last bloom            usually when freeze occurs in late Oct. Reproductive organs:            Stamens — numerous. Pistils — numerous. Pollen — fertile and            abundant unless temperatures exceed 85 to 90° F. where            pollen production can be reduced. Flower diameter: 3.07 cm.            Petal size: Length: 1.42 cm; width: 1.42 cm. Petal color:            White Group (155B) and Greyed-Purple Group (186C). Average            number flowers per cluster: 6.3. Average number of petals            per flower: 5.8. Number of sepals per flower: 5.2. Peduncle            length: 2.91 cm. Peduncle color: Yellow-Green Group (146C).            Cyme type: simple cyme.-   Fruit:    -   -   Floricane.—Maturity: first ripe date is from 2 June            extending 40-50 days. Size: medium-large, average fruit            weight of 6-7 g; primary fruit 4.2 g; secondary fruit 3.5 g;            tertiary fruit 3.9. Diameter of fruit at primary position on            inflorescence: equator 1.99 cm; base pole 1.89 cm; terminal            pole 1.51 cm. Diameter of fruit at secondary positions on            inflorescence: equator 1.63 cm; base pole 1.60 cm; terminal            pole 1.37 cm. Length (primary fruit): 2.55 cm. Shape:            slightly conical. Color: Black Group (202A). Drupelet size:            0.44 cm. Seed (drupe): average length 3.7 mm; width 2.1 mm;            dry weight 4.5 mg; color dry Greyed-Orange (164B). Soluble            solids: 10.2%. pH: 3.5. Acidity: 0.50 g/100 ml expressed as            citric acid. Processed quality: not evaluated for            processing. Uses: Intended for home garden use along with            local production that does not require fruit to be stored            for periods over 2-3 days.        -   Primocane.—Maturity: Average first ripe date is 15 July and            can fruit until frost depending on environment and cultural            management, similar to APF-12; in Aurora, Oreg., first ripe            date 10 Sept. with fruiting extending until mid October or            later depending on temperature; in Watsonville, Calif. first            ripe date 28 Aug. and fruiting extending until early            December. Size: medium-small, ave. 3.5 g; In Aurora, Oreg.            average size 9.1 g and in Watsonville, Calif. 4.4 g. Primary            fruit 3.2 g; secondary fruit 3.6 g; tertiary fruit 3.7 g.            Diameter of fruit at primary position on inflorescence:            equator 2.03 cm; base pole 1.77 cm; terminal pole 1.43 cm.            Diameter of fruit at secondary positions on inflorescence:            equator 1.90 cm; base pole 1.95 cm; terminal pole 1.43 cm.            Length (primary fruit): 2.55 cm. Shape: slightly conical.            Color: Black Group (202A). Drupelet size: 0.44 cm. Soluble            solids: 10.2%. pH: 3.7. Acidity: 0.50 g/100 ml expressed as            citric acid. Processed quality: Not evaluated for            processing. Uses: Intended for home garden use along with            local production that does not require fruit to be stored            for periods over 2-3 days.-   The Cultivar: The most distinctive features of the cultivar are    primocane-fruiting trait with attractive, large fruit with excellent    flavor, excellent plant health, and erect canes and enhanced    performance for fruit set and development in high summer    temperatures.

I claim:
 1. A new and distinct cultivar of blackberry plant named‘APF-77,’ substantially as illustrated and described.